Made mutation categories actually matter.

The primary mutation category now has significant influence. Traits from
other categories have a high chance of being removed. It is now very
difficult to end up with every single trait in the entire game.
Mutagens that cause mutation only in specific categories.

There are still a lot missing.
Added the remaining specific mutagens.

For now they use very general recipies.
Adds power armor Mk. II; makes power armor impervious to radiation
Adds Mk. II power armor to spawn lists
Only checks for radiation gear if the ground is irradiated
Merge MK II power armor.
Merge remote-tracking branch 'dda/master' into dda-master
Merge enhancements to mutation system.